This message is sent by an account owner to an account servicer (account servicing institution). The account owner may be a global custodian which has an account with its local agent (sub custodian), a local agent (sub custodian) which has an account with its clearing agent or registration provider or a financial institution which has an account with its local agent (sub custodian).
This message is used to:
instruct the modification of client details at the registration provider,
request the cancellation of a modification of client details which was previously sent by the account owner (the function of the message is CANC).